Retrofit as a Means for Reaching Net-Zero Energy Residential Housing in Greater Cairo

Abstract

The net-zero energy building (NZEB) concept is the future international goal for saving energy. It has led to many countries implementing policies designed to target efficient built environment. In Egypt, the built environment consumes more than 70.1% of total sold energy, with the residential sector consuming 54.9%. According to the Egypt’s annual electricity report, “the increase in the rate of sold energy of the residential sector, in comparison with industry and other purposes, is a result of the expansion of residential compounds and new communities.” This paper introduces the concept of retrofitting the existing residential gated communities to achieve zero energy residential community (ZEC) and discusses the integration of two strategies: energy efficiency retrofitting techniques to reduce energy demand and renewable ensergy systems to generate sufficient energy, resulting in nearly zero energy consumption on an annual basis. Design Builder is used to analyze the feasibility of integrating these two strategies in a single-family house, in a residential gated community in the eastern part of Greater Cairo. The simulation goes through two stages. The first stage, which itself consists of three phases, is focused on the building scale. During this stage, energy efficiency retrofitting techniques are investigated,and renewable energy (PV panels) is integrated. The second stage is focused on the community scale and involves applying the results on the whole residential community. The results achieved a reduction of 88.68% in energy consumption for the whole compound and proved that NZEB could be met by applying the two strategies. Moreover, a significant reduction in energy is shown when applying (NZEB) retrofit on a community scale.